// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_JSON_JSON_WRITER_H_
#define BASE_JSON_JSON_WRITER_H_

#include <stddef.h>

#include <string>

#include "base/base_export.h"
#include "base/macros.h"

namespace base {

class Value;

class BASE_EXPORT JSONWriter {
public:
    enum Options {
        // This option instructs the writer that if a Binary value is encountered,
        // the value (and key if within a dictionary) will be omitted from the
        // output, and success will be returned. Otherwise, if a binary value is
        // encountered, failure will be returned.
        OPTIONS_OMIT_BINARY_VALUES = 1 << 0,

        // This option instructs the writer to write doubles that have no fractional
        // part as a normal integer (i.e., without using exponential notation
        // or appending a '.0') as long as the value is within the range of a
        // 64-bit int.
        OPTIONS_OMIT_DOUBLE_TYPE_PRESERVATION = 1 << 1,

        // Return a slightly nicer formatted json string (pads with whitespace to
        // help with readability).
        OPTIONS_PRETTY_PRINT = 1 << 2,
    };

    // Given a root node, generates a JSON string and puts it into |json|.
    // TODO(tc): Should we generate json if it would be invalid json (e.g.,
    // |node| is not a DictionaryValue/ListValue or if there are inf/-inf float
    // values)? Return true on success and false on failure.
    static bool Write(const Value& node, std::string* json);

    // Same as above but with |options| which is a bunch of JSONWriter::Options
    // bitwise ORed together. Return true on success and false on failure.
    static bool WriteWithOptions(const Value& node,
        int options,
        std::string* json);

private:
    JSONWriter(int options, std::string* json);

    // Called recursively to build the JSON string. When completed,
    // |json_string_| will contain the JSON.
    bool BuildJSONString(const Value& node, size_t depth);

    // Adds space to json_string_ for the indent level.
    void IndentLine(size_t depth);

    bool omit_binary_values_;
    bool omit_double_type_preservation_;
    bool pretty_print_;

    // Where we write JSON data as we generate it.
    std::string* json_string_;

    DISALLOW_COPY_AND_ASSIGN(JSONWriter);
};

} // namespace base

#endif // BASE_JSON_JSON_WRITER_H_
